Not to spend too much time on “Negrogate,” but Slate’s Brian Palmer has a good history of the word “Negro” that’s definitely worth reading:

Colored was the preferred term for black Americans until WEB DuBois, following the lead of Booker T. Washington, advocated for a switch to Negro in the 1920s. (DuBois also used blackin his writings, but it wasn’t his term of choice.) Despite claims that Negrowas a white-coined word intended to marginalize black people, DuBois arguedthat the term was “etymologically and phonetically” preferable to colored or “various hyphenated circumlocutions.” Most importantly, the new terminology—chosen by black leaders themselves—symbolized a rising tide of black intellectual, artistic, and political assertiveness. (After achieving the shift in vocabulary, DuBois spearheaded a letter-writing campaign to capitalize his preferred term. In 1930—nine years before Harry Reid was born—the New York Times Style Book made the change.) Blacksupplanted Negro when the energy of this movement waned.

There was a period, from the early sixties to the very early seventies when things were in flux. Malcolm X gave a speech at one point about the black revolution vs. the negro revolution that pretty much drew the line in the sand. Martin Luther King’s followers, the folks who believed in advancement within the system by non-violent means still referred to themselves as negroes, while Malcolm’s followers, many of whom would have been considered radicals, militants or separatists, called themselves black. In MLK’s last speech in ’68, he’s still using the word Negro, but by that time, The Black Panthers, Stokely Charmichael, H. Rap Brown and others were leading a pretty large movement of people who would have considered that word “unacceptable.”

White people fell along the same lines. If you were young, or very liberal, you would be careful to use the word black. If you were somebody like Harry Reid, a 30something moderate Democrat with a mostly white constituency, you would have had to continue using the word Negro, lest voters think you were radical or a sympathizer to militants, a group that scared the crap out of most white folks.

By the mid-70s, most folks had switched to using black or Afro-American, but there continued to be a hard core of people who continued to use Negro. Some of those were southern bigots. Others were older white people who just never adapted. And apparently, some were older Negroes, who didn’t feel the need to redefine themselves. The same crowd that would have said, “his momma calls him Cassius, so I’m gonna call him Cassius.”

And apparently, there are still enough of that last group around where the census bureau felt the need to include that word on the latest form.